Method and apparatus for producing multivortex fluid flow

ABSTRACT

A multivortex device is provided comprising a series of adjacent plates with specially designed grooves and perforations which, when mounted transversely of a uniform fluid flow in a duct, results in the formation of numerous small adjacent flow vortices either all rotating in the same direction (co-vortices) or adjacent vortices rotating in opposite direction (counter-vortices). The fluid at the peripheries of adjacent co-vortices move in opposite directions and friction converts their rotational kinetic energy into turbulence within a few vortex diameters downstream from the multivortex device. The fluid at the peripheries of adjacent counter-rotating vortices move in the same direction, such that they roll upon one another substantially without friction and persist for many vortex diameters downstream from the multivortex device. The adjacent plates of the multivortex device can be provided with additional grooves and passageways which allow a second and/or third fluid to be introduced within each vortex. The high speed rotation of the first fluid can be used to act on the second and third fluids. A turbulent co-vortex field can be used to induce rapid mixing and chemical reaction, while a countervortex field can be used to remove particulates from the flow.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vortex flow apparatus and methods. Thepresent invention has been found particularly useful in producing amultivortex fluid flow from a uniform flow stream.

2. Description of the Prior Art

Current separation processes which employ vortex flow such as high speedcyclone separators rely upon centrifugal force of the vortex generatedby a gas flow to provide intimate and vigorous interaction between thegas stream and a suitable liquid medium which is confined in the cycloneseparator by the vortex generated by the gas flow. Such cycloneseparators rely upon the tangential injection of gas into the Vesselthrough submerged jets or sheets dispersing the liquid and resulting ina strong gas/liquid interaction. Similarly, the Pall Land and MarineCorporation of Newport, Florida produces an air cleaning apparatus inwhich a fixed vane in a vortex generator imparts a swirling motion to aflowing stream of contaminated air. The swirling motion causes theheavier dirt and water droplets to be thrown radially outward bycentrifugal force. The outer regions of the vortex are scavengedoverboard while the clean "eye" of the vortex is directed through acentral outlet tube. A panel array of such devices provides an efficientair cleaning system. Such current vortex flow generating devices relyupon a single vortex to provide mixing and/or separation.

SUMMARY OF THE INVENTION

The present invention relates to an apparatus and method for producingnumerous small, adjacent vortices ("multivortex fluid flow") from auniform fluid flow stream. The resulting vortices can all rotate in thesame direction ("co-vortices"), or adjacent vortices can rotate inopposite directions ("countervortices"). The apparatus comprises aseries of adjacent parallel plates adapted to be mounted in a positiontransverse to the uniform fluid flow. The plates include a series ofperforations and grooves which impart a multivortex fluid flow to theuniform fluid flow as it passes therethrough. The apparatus may beprovided with means to introduce a second or third fluid into eachvortex whereby the high speed rotation of the first fluid can be used toatomize the second and third fluids. For this purpose, the plates canalso be provided with additional grooves and holes which allow thesecond and/or third fluid to be introduced within each vortex, either atthe periphery of each vortex or at the center of each vortex. The highspeed rotation of the first fluid can thus be used to atomize the secondand third fluids. A turbulent co-vortex field can be used to inducerapid mixing and chemical reactions. A countervortex field can beemployed to remove particles from the fluid flow through the centrifugalforce which throws the particles into the space between adjacentvortices where gravity causes the particles to fall out. Typical usesfor a co-vortex generating device include paint mixing, paint or otherfluid spraying with or without an electrical charge, combustion of fuel,as well as other applications. Some potential uses of a countervortexgenerating device include precipitation of particulates, scrubbing ofnoxious gas molecules from gases, precipitation of condensible vaporsfrom gas, atomization, aeration and precipitation of ground water toremove volatile contaminants, as well as other applications. Suchmultivortex apparatus can also be used in efficient, compact fluid heatexchangers.

Co-vortices all rotate in the same direction so that the fluid at theperiphery of adjacent vortices is moving in opposite directions. Theresulting friction between adjacent vortices converts rotational kineticenergy into turbulence. The mean speed of the turbulence is initiallymuch higher than the forward drift speed of the fluids. The presentinvention allows other fluids to be injected into the eye of eachvortex, where the high speed rotation causes atomization and the fluidsare mixed violently by the induced turbulence.

One objective of the present invention is to use a co-vortex device toatomize, charge, spray, and collect liquid and solid paint particlesmore efficiently and less expensively. By having the pigment particlessuspended in air as the first fluid and a resin dissolved in solvent asthe second fluid, the present invention will mix the componentsnecessary to mass produce paint. Furthermore, if the air is hot enough,solvents will flash off and the result will be a charged dry powderpaint that can be easily collected electrostatically.

Another objective of the resent invention is to provide an inexpensive,efficient combustor in which air serves as the first fluid and fuel suchas pulverized coal or oil as a second fluid. The present inventionprovides for efficient atomization and mixing of the air and fuel toallow for efficient ignition.

Another objective of the present invention is to use a co-vortex deviceto finely atomize oil with air to form a dense turbulent plume of smoke.By electrically charging the oil drops, the neutral drops can be made tocluster around the charged drops and through clustering andelectrostatic and gravitational forces reduce the plume of smoke whendesired, thus providing the establishment and removal of a smoke screen.

The device of the present invention to produce multivortex fluid flowcan also provide a countervortex device which establishes a vortex fieldconsisting of a plurality of adjacent vortices rotating in oppositedirections so that the fluid at the periphery of adjacent vortices ismoving in the same direction. Such vortices roll upon one another withminimal friction and therefore persist for many vortex diametersdownstream. Such a countervortex device allows the particles in thevortices to be thrown outwardly by centrifugal force into the spacesbetween adjacent vortices where the particles tend to agglomerate andare removed by gravity.

One objective of the present invention is to use a countervortex deviceto precipitate suspended particles from gases. Another objective of thepresent invention is to use a countervortex device to scrub noxious gasmolecules from gas by injecting chemicals that react with undesirablemolecules and cause particulates to form.

Another objective of the present invention is to provide a pulverizedcoal combustor with hot gas clean up and a heat exchanger directly inline thereby drastically reducing the size and cost of a coal combustorWith associated air pollution control and energy conversion equipment. Amultivortex heat exchanger which employs high speed rotating fluids totransfer heat through copper tubes to another rotating fluid on theother side of the tubes is much shorter than conventional heatexchangers because the heat transfer rate is greatly increased by thehigh speed rotation of the fluid while the fluid travels slowly in theaxial direction.

Another objective of the present invention is to provide a multivortexheat exchanger to reduce the temperature of a gas until condensationoccurs, condensate droplets are precipitated in a counter-rotatingvortex fluid, and the gases are reheated in the heat exchanger. Thisresults in an extremely compact low energy solvent recovery device. Sucha solvent recovery device may be employed in a paint curing oven torecover both heat and solvent thereby reducing the size and cost ofovens for curing painted objects on production lines.

Another objective of the present invention is to employ acounter-rotating vortex device to atomize and aerate ground watercontaining volatile chemicals to conveniently and efficiently collectdroplets of fresh water.

Another objective of the present invention is to employ concentriccounter-rotating vortices to achieve internal atomization and chargingwithout wetting the walls of the vortex generator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged cross-sectional view of a section of a multivortexdevice of the present invention;

FIG. 2 is a plan view of a section of the downstream side of the first,plate of the multivortex generator of the present invention;

FIG. 3A is a plan view of a section of the upstream side of the secondplate of the multivortex device of the present invention;

FIG. 3B is a cross-sectional view of a section of the second plate ofthe multivortex device of the present invention;

FIG. 4A is a plan view of a section of the upstream side of the thirdplate of the multivortex device of the present invention;

FIG. 4B is e cross-sectional view of a section of the third plate of themultivortex device of the present invention;

FIG. 4C is a plan view of a section of the downstream side of the thirdplate of the multivortex device of the present invention;

FIG. 4D is a plan view of an alternate embodiment of a section of thedownstream side of the third plate of the multivortex device of thepresent invention;

FIG. 4E is a plan view of one set of openings for FIG. 4A;

FIG. 5 is a plan view of a section of the upstream side of the fourthplate of the multivortex device of the present invention;

FIG. 6 is a plan view of the downstream side of one embodiment of themultivortex device of the present invention showing the flow pattern;

FIG. 7 is a sectional side view of a combustor with heat exchangeremploying the multivortex device of the present invention;

FIG. 7A is a detail of the front portion of FIG. 7;

FIG. 8 is a side view partially in section of a water purificationapparatus employing the multivortex device of the present invention;

FIG. 8A is a cross-sectional enlargement of the multivortex deviceemployed in the aerator separator of FIG. 8;

FIG. 8B is a top plan view partially in section of the multivortexdevice, the aerator separator shown in FIG. 8;

FIG. 9 is a flow diagram of a system for removing condensable vaporsfrom air employing the multivortex device of the present invention;

FIG. 10 is a cross-sectional side view of a system for curing paintedparts, using the apparatus of FIG. 9;

FIG. 11 is a cross-sectional side view of the alternative embodiment ofthe multivortex device of the present invention;

FIG. 12 is a cross-sectional side view of an alternate embodiment of themultivortex device of the present invention; and

FIG. 13 is a cross-sectional side view of an alternate embodiment of themultivortex device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a multivortex device A of the present inventionadapted to allow the introduction of a second and third fluid to theflowing first fluid stream is shown. The apparatus includes four platesP1, P2, P3, P4 adapted to be oriented substantially perpendicular to theflow of a first fluid. Perforations in the plates and grooves andpassageways between adjacent plates convert the non-turbulent flow ofthe first fluid into small, closely spaced vortices as the first fluidflows through the plates.

The first plate P1 includes a plurality of holes 12 therethrough. Asecond fluid entrance 14 is also provided in the first plate P1 to allowthe introduction of a second fluid into a series of horizontal M andvertical N grooves cut into the downstream side 11 of the plate P1 (FIG.2). The plurality of holes 12 through plate P1 are oriented between theintersections of the vertical M and horizontal N grooves. Plate P1 ispreferably formed from a non-conductive material such as plastic.

The second plate P2 is preferably formed from a conductive material suchas metal if an electrostatic charge is to be created as discussed below.The upstream side 20 of plate P2 (FIG. 3A) includes a number of holes 22corresponding to the holes 12 of plate P1. Oriented around each hole 22are four smaller holes 24. Holes 24 are adapted to receive metallictubes 26 (FIG. 3b) which extend from plate P2 in a downstream direction.Holes 24 are adapted to align with the intersections of the horizontal Mand vertical N grooves of plate P1 when plate P1 is oriented adjacent toplate P2 with holes 12 and 22 in alignment (FIG. 1).

The next plate of the multivortex device of the present invention, plateP3, is preferably formed from a non-conductive material such as plastic.The third plate P3 of the multivortex device includes a plurality ofholes 32 therethrough oriented, and of such a size, so as to surroundthe metallic tubes 26 of the second plate P2 when plate P3 is orientedadjacent thereto (FIG. 1). The non-adjacent holes of each group of fourholes 32 on the third plate P3 are interconnected by a groove 34 in theupstream side 35 of plate P3. The grooves 34 are adapted to provide flowpassageways from each hole 22 of second plate P2 into the four adjacentholes 32 of third plate P3. The grooves 34 in third plate P3 intersectthe holes 32 tangentially so as to impart a rotational flow to the fluidpassing from the grooves 34 into the holes 32. The grooves 34 can beoriented such that the rotational flow in adjacent holes is the same(FIG. 4D) i.e. co-vortices or, the grooves 34 can intersect the holestangentially such that the rotational flow pattern in adjacent holes 32are opposite (FIG. 4A and 4E) i.e. counter-vortices. The downstream side31 of the third plate P3 (FIG. 4C) includes a series of horizontal I andvertical J grooves cut into the surface thereof providing a checkerboardtype pattern surrounding each of the holes 32. Extending from each hole32 are grooves K which intersect with the horizontal I and vertical Jgrooves as shown in FIG. 4C.

The fourth plate P4 of the present invention is preferably a conductivematerial such as aluminum or brass is shown in FIG. 5. The fourth plateP4 includes a plurality of holes 42 corresponding in size andorientation to the holes 32 in plate P3 and similarly adapted tosurround tubes 26 of second plate P2. The tubes 26 of plate P2 are sucha length that they extend substantially to the downstream surface 41 offourth plate P4. Fourth plate P4 also includes a fitting 46 to allow theinjection of a third fluid between third plate P3 and fourth plate P4into the horizontal I and vertical J grooves, through grooves K and intothe holes 42.

When the four plates P1, P2, P3, P4 of the multivortex device of thepresent invention are assembled as shown in FIG. 1, an apparatus isprovided which will convert a non-uniform fluid flow into a plurality ofadjacent vortices. A first fluid, typically air, flowing essentiallyperpendicular to the multivortex apparatus A flows through holes 12 ofplate P1, through the corresponding holes 22 of plate P2, through thegrooves 34 of plate P3 which lead the air flow into the holes 32 ofthird plate P3 tangentially to create a rotational flow pattern. Therotational forces created by the tangential entry of the air flow intothe holes 32 of third plate P3 are enhanced as the air flows aroundtubes 26 extending through the holes 32 of third plate P3 and on throughthe holes 42 of fourth plate P4. Thus, the uniform air flow on theupstream side 6 of the apparatus A is converted into a plurality ofvortices on the downstream side 8 of the apparatus A. The rotation ofadjacent vortices can be the same or opposite, depending upon thetangential entry of the air from grooves 34 into holes 32 of third plateP3. A second fluid can be injected into the center of each vortex, byinjecting a second fluid in the fitting 14 of first plate P1. The secondfluid flows between adjacent plates P1, P2 and through tubes 26 of plateP2 as shown by arrows 50 in FIG. 1. The second fluid atomizes as itleaves tubes 26 and the drops of this atomization are electricallyneutral. A third fluid can be injected into the exterior of eachindividual vortex. If desired the third fluid droplets, afteratomization, can be electrically charged. The third fluid is injectedinto fitting 46 of fourth plate P4 into the horizontal I and vertical Jgrooves in the downstream side 31 of third plate P3. These grooves allowinjection of the third fluid into the aligned holes 32 of third plate P3and holes 42 of fourth plate P4 where the rotating air forces the fluidto flow as a thin film along the wall of the holes 42 in the fourthplate P4. If desired, a voltage differential may be applied across themetallic second plate P2 and the metallic fourth plate P4 to establish aradial electric field Q (FIG. 1) between metal tubes 26 and the walls ofthe holes 42 in the metal fourth plate P4. This electric field Q wouldbe established by attaching conductors 52, 54 to second and fourthplates P2, P4, respectively. This electric field Q through the thin filmof fluid induces a surface charge that remains on the fluid drops afteratomization occurs at the exit of the holes 42. Although the drops fromthe tubes are electrically neutral, they tend to cluster around thecharged drops from holes 42 due to the electrostatic attraction betweencharged drops and induced dipoles in the uncharged drops. Turbulenceincreases the rate of clustering, and the rotational kinetic energy ofthe co-vortices is converted into high speed turbulence within a fewvortex diameters. The shape of the spray is determined by the pattern ofvortices in the space.

The advantages of this method of atomizing, charging, mixing andspraying fluids are:

(1) Versatility (conventional methods require special equipment for eachtype of fluid)

(2) Low operating cost (vortex atomization requires less power thanaxial flow atomization to achieve the same drop size for the same fluidflow rate)

(3) Low construction cost (plastic and metal plates can be molded andassembled very cheaply)

(4) Safety (Inductive charging can be done inside the device with anapplied voltage several times less than that required by conventionalelectrostatic spray devices)

(5) Superior coatings (conventional electrostatic spray devices achievehigh collection efficiency at the expense of uniform coating onirregular surfaces, but the highly turbulent slow moving cloud ofcharged particles produced by this device penetrates deeply into holes,crevices and coats sharp edges and points to the same thickness on allsurfaces, with equally high collection efficiency.)

This device can be used to mass produce paint, to mix pigment particlesdispensed in air with resins dissolved in solvents. The resultingcharged paint particles can be collected electrostatically for futureuse, or they can be used as produced. If the atomizing air issufficiently hot, the solvents can be flashed off to produce dry paintparticles that can be collected easily and used later. A co-vortexdevice which employs grooves in third plate P3 as shown in FIG. 4D whichresults in adjacent vortices flowing in the same directions can be used,for example, to carry out other chemical reactions. For example,pulverized coal or fuel oil can be burned in such a device, withignition achieved by increasing the applied voltage between tubes 26 andfourth plate P4 sufficiently to induce sparks 56. A conventional heatexchanger coil or coils in the path of the hot turbulent exhaust gaswould serve as a very efficient steam generator because the heattransfer rate is enhanced by the high level of turbulence.

Such a co-vortex device could also be useful as a smoke generator. Ifone of the fluids atomized is oil, because of its low surface tension,an extremely fine, even submicron, droplet could be produced that wouldquickly diffuse over a wide area due to turbulence. To disperse such acloud, the device could then be employed to charge oil droplets thatwould cause the neutral droplets to cluster around the charged onesresulting in dispersion of the smoke screen due to clustering,gravitational and electrostatic settling.

For example, a co-vortex spray device having the following dimensionsand operating characteristics has proven highly effective. The fourplates P1, P2, P3, P4 were dimensioned 1/8 inch thick and 1 inch wide by10 inches long. The first plate P1 was provided with sixty-four 1/8 inchvortex holes 12 on 1/4 inch centers in a pattern two holes by thirty-twoholes. The crisscross and tangential inlet slots I, J, K in the thirdplate P3 were 1/32 inch wide and 1/64 inch deep. The metal tubes in eachsurrounding hole in the second plate P2 were 1/16 inch in diameter. Withan inlet air pressure of 30 psig, rotating air speed would beapproximately 300 meters per second and an actual vortex speed ofapproximately 12 meters per second. The air flow rate would beapproximately 26 standard cubic feet per minute. Such an apparatus canfinely atomize as much as 10 grams per second (approximately equal to 9gallons per hour of liquid), producing droplets of approximately 10microns in radius with a charge/mass ratio of approximately 10⁻⁴coulombs per kilogram with a current of approximately 10 microamperesflowing from the device to grounded surfaces. With a droplet radius ofapproximately 10 microns, the mobility of the charged drop isapproximately 10⁻⁶ meters squared per volt second which would result ina high collection efficiency.

In a counter-rotating device (FIG. 4A), the grooves 34 would direct airtangentially to each four adjacent vortex holes 32 so that the air inadjacent vortex holes rotates in opposite directions. In such acountervortex arrangement, the resulting vortices roll upon one anothersubstantially without friction almost like ball bearings, therebypersisting for many diameters downstream. Particles in the vortices arethrown by centrifugal force into the spaces between adjacent vorticeswhere they tend to agglomerate and where gravity induces the particlesto leave the spaces in a downward direction 60 (see FIG. 6). Hence, thevortices actually pump particles down at a speed of approximately Vdivided by 4 compared to the slow axial speed U.

As an example, FIG. 7 shows a pulverized coal combustor with hot gascleanup and heat exchanger directly in line in which such acountervortex multivortex apparatus is employed. The countervortexdevice 70 is located at the inlet 72, in which air is injected as thefirst fluid. Pulverized coal mixture 73 is injected as the second fluid.The mixture 73 forms a slow moving film along the vortex holes that isexposed to high speed rotation of hot air after initial ignition, withinthe holes. In such an apparatus, the oxidation is extremely rapidbecause the particles are small and because the sheer stresses and masstransfer rates are very high. The coal is reduced to ash before itleaves the holes 42; the ash is then thrown into the spaces betweenadjacent vortices and with the help of gravity is deposited in a hopper273 below. In this application, there is no need for the tubes 26 asshown in FIG. 1, however, a third fluid or chemical may be injectedthrough fitting 46. Injection of a fluid such as ammonia for the purposeof converting sulfur dioxide into ammonia sulfate particles--that can beprecipitated and also can suppress nitrogen oxides that might otherwisebe formed--can be employed. In place of the metal employed in secondplate P2 and fourth plate P4, a graphite impregnated ceramic materialmay be employed to better resist the temperature and erosion withoutsacrificing electrical conductivity. Immediately downstream of theprecipitator section 76, which is preferably approximately ten vortexdiameters long, there is a heat exchanger 78 which includes copper tubes77 in line with the counterrotating vortices. Rotating flow enteringsuch tubes 77 rapidly transfers heat through the tube walls and the heatmay be picked up by water evaporating on the outside of such tubes 77 togenerate steam. The length of such a heat exchanger 78 is much shorterthan a conventional exchanger because the heat transfer coefficient ishigh as a result of the high Reynolds number associated with the highspeed rotation of the hot fluid. The efficiency of the heat exchanger 78is further enhanced by the slow axial movement of the hot fluid. Tofurther improve the efficiency of the heat exchanger 78, water 379 canbe injected as a spray 380 through narrow annular gaps (not shown)around each tube at the downstream end 79 to flow upstream (arrow U inFIG. 7) as a thin film along the tubes 77. Evaporation of the waterforming drops of water and vapor or wet steam that continues to dry outas it moves in the upstream direction toward the exhaust 279 of theexchanger 78. As long as there is not a blanket of water on the heatexchanger tubes 77, evaporative cooling of the tubes 77 can remove heatvery rapidly, and the heat exchanger 78 need only be on the order of tenvortices diameters long. Therefore, the combustor with hot gas cleanupand heat exchanger may have overall length of approximately thirty-fivevortex diameters, such as four inches for 1/8 inch vortices. Such acombustion system may be employed to destroy pulverized and liquidhazardous waste as well as to burn fossil fuels. The advantages of thiscombustion system are:

(1) Versatility (this system can be used to destroy pulverized andliquid hazardous wastes as well as to burn fossil fuels)

(2) High combustion efficiency (the high level of turbulence in thecombustion boundary layer assures rapid and complete oxidation in a veryshort distance)

(3) Efficient Emission Control (Unlike conventional gas cleanup systems,particulates are removed immediately, and well known chemical techniquescan be used to convert noxious gases into particulates that also can beremoved within a very short distance; e.g. ammonia to form ammoniumsulfate particulates and to suppress nitrogen oxide and mixing alimestone with the coal to form calcium sulfate particulates that caneasily be removed.)

(4) More compact and efficient steam generation (conventional systemsuse much larger heat exchangers and periodically they have to be shutdown for cleaning, which is not necessary with this device).

(5) There is the option of directly driving a gas turbine with the hotclean gas rather than generating steam.

(6) Easy scale-up (the capacity of this system is increased by simplyincreasing its cross sectional area).

Such a combustor exhibits a high combustion efficiency due to the highlevel of turbulence in the combustion boundary layer which assures rapidand complete oxidation in a very short distance. Further, such acombustor exhibits low emissions due to the particulate removal as wellas the use of chemical techniques to precipitate and remove noxiouschemicals which may be incorporated directly within the combustor.

As an example, a small combustor with a square array of six by six holesin plates P1 and P2 1/8 inch in diameter in a duct approximately 11/2inches square with a pressure drop of twenty inches of water createsvortices having a rotational speed of approximately eighty meters persecond and an axial speed of approximately ten meters per second withthe cross grooves in plate P3 being 1/32 inch wide and 1/16 inch deep.The air flow in such an apparatus would be approximately twenty standardcubic feet per minute, and the system could burn pulverized coal at therate of approximately one gram per second generating approximately 10⁴watts of thermal power. A 10⁶ watt system would simply be scaled up onehundred times. Such a scale up would result in a cross-sectional area offifteen by fifteen inches for the duct size. The length would remain thesame.

In addition to being used to burn pulverized coal, such a system couldbe used to burn hazardous waste with the vortex generator andprecipitator section used to clean particulates and noxious gases out ofthe exhaust. The small system described above has demonstratedefficiencies in excess of 99% in removing tobacco smoke, oil and watermist, and AC fine dust (a standard dust for evaluating effectiveness ofdust filtration) from an air stream.

FIGS. 8, 8A, and 8B show an alternative use of the multivortex device ofthe present invention in which the multivortex apparatus is employed forremoving volatile chemicals from water by aeration. Such an apparatusemploys a vertical orientation of the multivortex device. A fan 80 atthe bottom of the device D introduces air to flow from top to bottom. Acountervortex field is established, as previously set out, with a dirtywater stream injected along the walls of the vortex holes. In the vortexholes, just before atomization any volatile chemicals in the water flashout of the thin film of water. Mass transfer of volatiles from the dirtywater stream is extremely rapid due to the high level of turbulence atthe interface between the fluid film on the wall and the high speedrotating air stream. As the thin film of water leaves the vortex holes,the water is atomized and thrown into the spaces 81 between adjacentcounter-rotating vortices 82 (FIG. 8A). After approximately 10 vortexdiameters, the vortices 82 enter a plurality of thin wall tubes 83 thatlead the air to the exhaust fan 80. The clean water 81 agglomerates andfalls between these tubes 83 to flow out of the exhaust pipe 84. A checkvalue (not shown) would be located in air exhaust pipe 84 to prevent airfrom being sucked into the device during start up. Such a multivortexaerator/separator when compared to a conventional packed counterflow airstripping tower is much more economical. A typical packed counterflowair stripping tower capable of cleaning twenty-five hundred gallons perminute is nine feet by nine feet by twenty-five feet tall, while amultivortex gas aerator/separator with a similar capacity would beapproximately 61/2 by 61/2 by 21/2 feet tall, or twenty times smaller involume. Both the conventional counterflow tower and the multivortexaerator/separator have an air/water ratio of thirty by volume and apressure drop of approximately three inches of water. Both devicessimilarly have a fan power requirement, such as approximately fivehorsepower, however the power required to pump the water into themultivortex aerator/separator is approximately 1/10 that required topump water into a conventional tower because of the height ratio. Forexample the conventional tower would require 20,000 lbs/min×25.5feet=510,000 ft-lbs/min, or 5 horsepower.

Theoretically, the ratio of final to initial concentration of volatilechemicals remaining in the water is approximately n'_(f) /n'_(o)=(RT/H)(V'/V) where V/V' is the air to water ratio by volume, H isHenry's constant, R is the universal gas constant, and T is temperature.For a typical contaminant like TCE, H/RT=1/2.22, and with V/V'=30 andn'_(f) /n'_(o) =0.074, a removal efficiency of 92% is achieved. Thelength required to achieve this efficiency is found according to thefollowing equation: L approximately equals 5duV'/4cV where d equals thevortex diameter of approximately 3×10⁻³ meters, u equals axial speed often meters per second, and c is the mean speed of turbulence induced bythe rotational speed v, which is approximately 0.01 v or approximately0.32 meters per second induced by a rotational speed of v equal to 32meters per second. Therefore, L equals approximately 0.004 meters or anL/d ratio of approximately 1.33. Similar results could be obtained whenanalyzing combustion or other chemical reactions between a thin film ofreactant and a high speed rotating gas. For example, for combustion, onewould consider the carbon and hydrogen leaving the thin film to form CO₂and H₂ O in air.

The aerator described in FIG. 8 has many other uses. For example, if alow viscosity silicon oil, having extremely low vapor pressure, is usedin place of water, air can be de-humidified and cleansed of dust, pollenand other suspended particulates as the vortices encounter the thinfilms of oil. De-humidification occurs because water molecules strikingthe oil surface form condensate droplets that are more dense than theoil, so centrifugal force drives them into the oil films. Then, theliquid water cannot re-evaporate back into the air. The water can laterbe separated from the oil in a settling tank like the one shown in FIG.9 described below.

This system could be used as an air-conditioner by introducing theproper amount of water spray into the de-humidified exhaust air, causingcooling by evaporation. Air-conditioners of this type would haveadvantage of compactness, quietness, and lower cost compared toconventional air-conditioners, because the air compressor and severalheat exchangers would be unnecessary. Furthermore, the inlet air filterthat has to be periodically removed and cleaned would be eliminated;instead, the dirt would be screened from the oil entering the settlingtank, and this filter would be easy to remove and clean or discarded,because it resembles the oil filter in an automobile.

FIG. 9 shows an alternate use of the multivortex apparatus of thepresent invention wherein a multivortex heat exchanger including asubsystem for recycling refrigerated solvent is disclosed. The systemincludes a solvent container C, which is made of a material, such asplastic or glass, that is resistant to the solvent. At the top ofcontainer C are two compartments 91, 93 separated by a disk 90. Theupper compartment 91 contains the exhaust gas which exits through anoutlet tube 92, while the incoming contaminated gas enters the lowercompartment 93 through an inlet tube 94. A heat exchanger 95 is justabove the lower compartment 93. Tubes 97 extending from the exhaust side98 of the heat exchanger 95 are mounted through the lower compartment 93into the upper compartment 91. The contaminated gas in the lowercompartment 93 enters holes 96 in the heat exchanger 95 through smalltangential inlets which cause the gas to spin in a vortex in each hole96. At the exit of each hole 96, a hypodermic needle 99 injectsrefrigerated solvent from a pool 101 into the vortex. The solvent isatomized into tiny droplets by the high speed rotating gas. Thesedroplets are thrown radially outwardly by centrifugal force into thespace between adjacent vortices where they agglomerate and fall bygravity into the pool 100 below. The rotating gas continues to rotate inthe same direction and leaves the lower compartment 93 throughtangential inlets in the entrance of the exhaust tubes 95 which arelocated between the inlet holes 96. The spinning gas in the exhausttubes 95 and in the inlet holes 96 cause heat transfer to be very rapid,hence, the heat exchanger 95 can be made sufficiently short such thatthe speed of rotation decreases only by a factor of two. By making thegas in adjacent inlet holes 95 spin in alternately clockwise and counterclockwise directions, adjacent vortices roll upon one another withoutfriction and the rotation persists as the gas is turned and goes outthrough the exhaust tubes 95. The pool 100 of collected solvent containsthe condensed solvent vapor along with other condensibles such as watervapor and some particulates. The solvent in pool 100 is removed througha tube 103 which is directed through the center of a counterflow heatexchanger 104 to the bottom of a settling tank T in which the water andthe particulates W separate from the solvent which generally floats ontop. The level of liquid in the settling tank T is kept equal to thelevel of collected liquid in the collector. Liquid is pumped by pump Pfrom the top of the settling tank T to the counterflow heat exchanger104 where it is cooled by the exhaust liquid flowing through tube 103.The partially cooled solvent is then flows to a refrigerator system Rwhere it is further cooled before being directed into the lowercompartment 93 of the cylinder C where the inlets to the hypodermicneedles 99 are located. Thus, the only heat that has to be removed bythe refrigerator system R is that released by the condensation of vapor,plus that due to the heat exchanger losses which can be quite small. Avalve W is provided in the settling tank through which water andparticulates can be removed and a valve X in the top of the settlingtank T allows excess solvent to be added or removed.

One advantage of such a system is that a clean exhaust gas is providedwhich is approximately the same temperature as the dirty inlet gas andthe collected contaminants are also close to this temperature. Also, thesystem can be scaled up by increasing its cross-sectional area so thatit can handle a larger air flow rate, but the size of the tubes and thenumber per unit area would remain constant. It should be noted that thelarger the number of tubes, the less effect the walls in the scrubbingsection have upon the process.

It also should be noted, that the heat exchanger 95 is preferably alamination of conductive materials, such as copper sheets, separated bythin layers of thermal insulation so that the heat cannot flow axiallyfrom one end to the other. This is highly desirable because the heatexchanger is preferably very short, and a large temperature differenceis preferably maintained from one end to the other while at the sametime, heat must be able to flow freely from the inlet tubes to theoutlet tubes.

The simplicity of the construction and the compactness of the system,combined with relatively low power input to produce the rotating flowsand to run the refrigerator R, yield a very competitive system both withrespect to installation and operating cost compared to competing systemssuch as granulated, activated carbon absorption, condensers andafterburners with or without catalyst and/or heat recovery.

In addition, a solvent separation system can be employed, shown in FIG.10 as a solvent recovery system in an assembly line type of paintspraying operation. Such an apparatus may be employed to recover solventfor reuse and to prevent the release of the solvent into the atmosphere.

FIG. 10 is a schematic showing how painted parts on a mass productionline can be cured in an oven in which most of the heat recovered fromthe parts and most of the solvent liberated by the cured paint is alsorecovered. The system includes a long thermally insulated tunnel 180through which the parts 190 pass on a conveyor 195. Air is blown throughthe tunnel 180 by blowers 200, 205 in the opposite direction in whichthe parts 190 are moving. Deflectors 210 are located on the walls 215 ofthe tunnel 180 that induce turbulence which increases the rate of heatand mass transfer. This turbulence allows the tunnel 180 to beshortened. The air is sucked out at the other end of the tunnel 180through multi-vortex solvent recovery systems 220, 225 like that shownin FIG. 9. In the center of the tunnel 180, there is a heat source, suchas heater 230 to add sufficient heat to maintain the curing temperatureat the desired level in this region. However, as the hot parts 190 leavethis region, they lose heat to the incoming cool air and as the hot airleaves this region, it loses heat to the incoming cool parts 190. Theadvantage of the system is that the only thermal energy input requiresis a small amount that is not recovered in the counter flow heatexchanger. Also, the solvent collected may be reused without the needfor expensive air pollution control systems typically necessary toprevent solvent emissions.

FIG. 11 shows an alternate embodiment of the present invention wherein amultivortex device for pumping, atomizing, charging, and spraying twofluids is disclosed. The device includes four adjacent disks D1, D2, D3,D4 with the second disk D2 and the fourth disk D4 preferably ofconductive metal materials. The disks D1, D2, D3, D4 are cementedtogether. The fourth disk D4 has a hole 110 in fluid communicationwithin a metal tube 104. Tube 104 extends along the center line up tobut not into disk D1. A first fluid enters hole 110 in disk D4 and flowsthrough metal tube 104. A second fluid enters hole H2 in disk D4 andflows into the space 106 between disk D4 and disk D3. Disk D3 includes aplastic tube 108 concentric with metal tube 104. The second fluid flowsthrough the annular gap G1 between tube 104 and tube 108 to the end ofthe tubes. An applied voltage between metal disks D4 and D2 byconductors 113, 115 establishes a radial electric field through thisflowing fluid, and a surface charge is induced that remains on theliquid drops after atomization. The fluid emerging from metal tube 104is also atomized, but the drops have no charge. However, turbulence andelectrostatic dipole attraction cause the uncharged drops to clusteraround the charged drops emerging from annular gap G1. Air used foratomizing enters the apparatus through opening H3 in disk D4 near itsperiphery and passes through aligned openings H4, H5 in disk D3, D2,respectively. The air is directed through a slot 117 located on theupstream side of disk D2 which directs the air tangentially into thecenter opening 112 of disk D2 so as to rotate the air in a clockwisedirection in the annular gap G2 between the plastic tube 108 and thecentral opening 112 in the metal disc D2. A similar slot 119 in theupstream face of disk D1 leads air from opening H5 tangentially into thecenter opening 114 in disk D1 which is slightly larger than the centralopening 112 in the disk D2, so that air rotates in a counterclockwisedirection in the annular gap G3 between the clockwise vortex from gap G2and the central opening 114 in disk D1. The inner clockwise vortexatomizes the fluid within the device and the outer counterclockwisevortex prevents drops from reaching and wetting the wall of theapparatus. A few vortex diameters downstream, the kinetic energy ofrotation is converted to turbulence, and the axial speed of the chargedspray is relatively slow, ideal for painting.

It can be shown theoretically that vortex atomization produce dropletsof a radius approximately equal to (3SIGMAr/ RHO₁ V²)1/2(1+m₁ /m_(a))where SIGMA is a surface tension of the liquid, r is the radius at whichatomization occurs, v is the rotational speed at that radius, RHO₁ isthe density of the liquid, m₁ is the mass flow rate of the liquid, andm_(a) is the mass flow rate of air. In such a configuration, theadvantage is achieved by the fluid's being atomized within the devicewhere r remains as small as possible and v remains as large as possible,whereas when atomization is external, as in FIG. 2, the mean value of ris somewhat larger and v is somewhat smaller. Such an apparatus allowsthe concentric oppositely rotating vortices to atomize the liquidslightly inside the device without wetting the device. As a dropletrapidly moves radially outward due to centrifugal force, it encounters amixing zone at the interface between the oppositely rotating vortices inwhich the rotational speed is close to zero, and the particles stopdrifting outward just long enough to clear the opening 114 of theapparatus. Such a configuration can be effective with a single openingor multiple openings because of the stream coherence provided by theoppositely rotating concentric vortices. Further, vacuum is produced bythe oppositely rotating vortices at the exit of the fluid tubes, hence,liquids can be pumped through the device.

The counter-vortex device can also be used to remove condensible gasmolecules from gases by spinning the gas so fast that static temperaturefalls below the dew point and condensate forms and precipitates. Forexample, the decrease in static temperature is DELTA T=RHOv² /2 c_(p).

where c_(p) is approximately 1010 joules/kg-°C. is the heat capacity ofair at constant pressure, RHO approximately equal to 1 kg/m³ is thedensity of air, and if v is approximately 300 m/s for the rotationalspeed of the free vortices, then DELTA T is approximately 50° . Hence,starting with the gas at room temperature, the static temperature may bedropped to -25° C.. This is sufficient to condense water and many othersolvent vapors.

The pressure drop required to do this is DELTAp approximately equalsRHOv² /2 and with RHO approximately equalling 1.3 kg/m³, DELTApapproximately equals 5.85×10⁴ n/m² or approximately equals 0.552 atmos.or approximately equals 8.11 psig.

Further, if these vortices were confined within tubes, the condensatedroplets upon striking the tube walls would reevaporate because thetemperature there is close to the stagnation temperature of the gas.Precipitation of condensate droplets is only possible because the freevortices of a countervortex device roll upon one another withoutgenerating friction and the static temperature remains low.

FIGS. 12 and 13 disclose alternate embodiments of the multivortexgenerating apparatus of the present invention. In FIGS. 12 and 13, themetallic tubes 26 of plate P2 shown in FIG. 1 are replaced by ahypodermic needle electrodes 150, 160, respectively, at high voltagesextending at least to the lip 156 of plate P3. P3 would be the metalattractor electrode along which flows a thin film of either conductiveor nonconductive liquid directed by lip 156 and the rotating air throughit. Further, a lip 156 is provided on plate P3 around each hole 32. FIG.12 discloses an apparatus for use when the fluid to be introduced intothe air vortex is conductive wherein needle electrode 150 extendssubstantially through the downstream surface plate P4. FIG. 13 disclosesan apparatus for use when the fluid to be introduced into the rotatingvortex of air is nonconductive, wherein the needle electrode 160 extendssubstantially to the downstream extension of lip 156 of plate P3. Theuniform radial electric field induces a surface charge on the conductiveor nonconductive fluids so that droplets formed at the exit also have acharge. No current flows from either of the hypodermic tubes 150, 160 tothe liquid through the air because the applied voltage is kept lowenough preventing air from breaking down. For nonconductive fluids wherethe hypodermic tube 160 does not extend beyond vortex plate P3, theelectric field is so intense at the tip of the tube 160 that a coronadischarge from the tip sends charged molecules of one polarity to coatthe surface of the nonconductive fluid flowing along the attractor wall.As the fluid breaks up at the exit, the drops carry away the charge.

Because many varying and different embodiments, as illustrated above,may be made within the scope of the inventive concept herein taught,including equivalent structures of materials hereafter thought of, andbecause many modifications may be made in the embodiments hereindetailed in accordance with the descriptive requirements of the law, itis to be understood that the details herein are to be interpreted asillustrative and not in a limiting sense.

What is claimed is:
 1. A multivortex fluid flow apparatus for use withat least two fluids, comprising:a series of adjacent plates; each ofsaid plates having a series of interconnected grooves and perforations,said plates having means for acting on the fluids through multipleadjacent vortices generated in the flow of the first fluid; a firstinlet to said plates for the inlet of the first fluid; a plurality ofoutlets from said plates for the outlet of at least a portion of thefirst fluid; a second inlet to said plates for the inlet of the secondfluid; and said outlets includes an outlet for at least a portion of thefirst and second fluids; said series of plates includes four plates andwherein said second plate inlet includes an opening through said firstplate; said first inlet includes a first set of substantially evenlyspace perforations through said first plate; said first plate includes afirst series of intersecting horizontal and vertical grooves cut intothe downstream side of said first plate, said opening oriented tointroduce the second fluid into said grooves and said first set ofperforations oriented between the intersections of said grooves; saidsecond plate includes a second set of perforations corresponding inorientation to said first set of perforations; a third series of sets ofperforations each set being oriented around one perforation of saidsecond set of perforations; each perforation of said third sets ofperforations having a tube at the downstream outlet, and the upstreaminlet of each perforation of said third sets of perforations beingaligned with the intersection of one of said horizontal grooves with oneof said vertical grooves of said first series of intersecting horizontaland vertical grooves when said first plate is oriented adjacent saidsecond plate with said first and second set of perforations aligned;said third plate includes a fourth set of perforations oriented and ofsuch a size so that each of said fourth set of perforations surround acorresponding one of said tubes when said second plate is orientedadjacent to said third plate; a second series of crossing grooves cutinto the upstream side of said third plate and adapted to provide flowpassageways from said second set of perforations into said fourth set ofperforations, said grooves intersecting said fourth set of perforationsand having vortex means for imparting rotational flow to the first fluidpassing from the second series of grooves to said fourth set ofperforations; said fourth plate includes a fifth set of perforationsoriented and of such a size so that each of a said fifth set ofperforations corresponds in size and orientation to the correspondingperformation of said fourth set of perforations and surrounds acorresponding one of said tubes when said fourth plate is adjacent saidthird plate.
 2. The apparatus of claim 1, wherein there is a third fluidand: said third plate includesa third series of intersecting horizontaland vertical grooves cut into the downstream side of said third plate,said fourth set of perforations being surrounded by said third series ofgrooves; a fourth series of grooves cut in the downstream side of saidthird plate and intersecting said third series of grooves to providefluid communication therebetween; and said fourth plate includes a thirdinlet to said plates, said third inlet including a second perforationthrough said fourth plate oriented to permit the third fluid to flow insaid fourth series of grooves.
 3. The apparatus of claim 1 wherein saidvortex means includes tangential intersections of said second series ofgrooves with said fourth set of perforations.
 4. The apparatus of claim1, wherein said vortex means imparts co-vortex rotational flow to thefirst fluid.
 5. The apparatus of claim 1 wherein said vortex meansimparts counter-vortex rotational flow to the first fluid.
 6. Amultivortex fluid flow apparatus for use with at least three fluids,comprising:a series of adjacent plates; each of said plates having aseries of interconnected grooves and perforations, said plates havingmeans for acting on the fluids through multiple adjacent vorticesgenerated in the flow of the first fluid; a first inlet to said platesfor the inlet of the first fluid; a multiplicity of outlets from saidplates for the outlet of at least a portion of the first fluid; whereinsaid series of plates includes four plates and there is included asecond inlet and a third inlet to said plates for the inlet of thesecond an third fluids, said third plate including a first set ofgrooves running substantially along said downstream face of said thirdplate; a first gap between said first plate and said second plate; saidsecond inlet including a perforation through the first of said platesand in fluid communication with said first gap; a first and secondconcentric tubes mounted in and between said second and third plates andinterior concentric tube in fluid communication with said first gap; asecond gap between said second plate and said third plate; said firstinlet including a perforation through the first of three of said platesand in fluid commmunication with said second gap; at least one openingin said fourth plate coxial with and adjacent said third plateperformations and of diameter greater than the diameter of said thirdplate perforations; and a third gap between said third plate and saidfourth plate in fluid communication with said third inlet and saidgrooves; said outlets including an outlet for at least a portion of thethree fluids.